Catheters for performing a therapeutic embolization procedure typically have detachable, inflatable balloons formed of latex or a C-FLEX.TM. material. During an embolization procedure, the detachable balloon is attached to the distal end of a delivery catheter and positioned at the treatment site using a visualization aid such as fluoroscopy. Once positioned, the balloon is filled with a solidifying gelatinous fluid until a predetermined pressure is reached within the balloon for forcing the balloon valve closed and away from the delivery catheter. In this manner, the balloon is detached from the delivery catheter. The gelatinous fluid quickly solidifies for achieving long-term occlusion of the blood vessel at the treatment site.
A problem with these detachable balloons is that there is no positive means of detachment. Detachment of a balloon depends on fluid forces in the balloon and in the bloodstream at the treatment site. Blood flow surrounding the balloon on the delivery catheter potentially causes premature balloon detachment. As a result, the balloon is not filled with gelatinous fluid, and the balloon valve is not sealed. The partially collapsed balloon moves through the vascular system of a patient to an undesirable site such as the heart, brain, or lungs to cause a heart attack, stroke, or pulmonary embolism and possibly death.